A basal ganglia model of freezing of gait in parkinson’s disease

Vignesh Muralidharan, Pragathi Priyadharsini Balasubramani, V. Srinivasa Chakravarthy*, Ahmed A. Moustafa

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingChapterResearchpeer-review


Freezing of gait (FOG) is a mysterious clinical phenomenon seen in Parkinson’s disease (PD) patients, a neurodegenerative disorder of the basal ganglia (BG), where there is cessation of locomotion under specific contexts. These contexts could include motor initiation, i.e., when starting movement, passing through narrow passages and corridors, while making a turn and as they are about to reach a destination. We have developed computational models of the BG which explains the freezing behavior seen in PD. The model uses reinforcement learning framework, incorporating Actor–Critic architecture, to aid learning of a virtual subject to navigate through these specific contexts. The model captures the velocity changes (slowing down) seen in PD freezers upon encountering a doorway, turns, and under the influence of cognitive load compared to PD non-freezers and healthy controls. The model throws interesting predictions about the pathology of freezing suggesting that dopamine, a key neurochemical deficient in PD, might not be the only reason for the occurrences of such freeze episodes. Other neuromodulators which are involved in action exploration and risk sensitivity influence these motor arrests. Finally, we have incorporated a network model of the BG to understand the network level parameters which influence contextual motor freezing.

Original languageEnglish
Title of host publicationComputational Neuroscience Models of the Basal Ganglia
EditorsV. Srinivasa Chakravarthy, Ahmed A. Moustafa
Number of pages17
ISBN (Electronic)978-981-10-8494-2
ISBN (Print)978-981-13-4168-7, 978-981-10-8493-5
Publication statusE-pub ahead of print - 22 Mar 2018
Externally publishedYes

Publication series

NameCognitive Science and Technology
ISSN (Print)2195-3988
ISSN (Electronic)2195-3996


Dive into the research topics of 'A basal ganglia model of freezing of gait in parkinson’s disease'. Together they form a unique fingerprint.

Cite this